Packaged charcoal fuel



United States Patent 3,351,443 PACKAGED CHARCOAL FUEL Walter Patrick Gramm, Winnetka, and Lowell E. Wills,

Chicago, Ill., assignors to Great Lalres Carbon Corporation, New York, N.Y., a corporation of Delaware No Drawing. Filed May 3, H66, Ser. No. 547,162 5 Claims. (Cl. 44-40) This invention relates to a method for preparing a selfigniting, or self-kindling package of a charcoal type fuel particularly useful in the barbecue cooking of meat, and to the packaged products produced by this process. More particularly this invention relates to a method for preparing charcoal, either in the form of lumps or in the form of briquettes which are impregnated with a liquid hydrocarbon fuel and then sealed in a multi-ply laminated plastic package which can be easily ignited with a match and which, when so ignited will in turn ignite the hydro canbon fuel and the solid portion of the charcoal.

Charcoal, either in the form of lumps or briquettes, has become popular as a fuel for broiling meat, either indoors or outdoors. Because such a fuel is difiicult to ignite, it has been usual practice to employ liquid, combustible starter fuels which are usually sold in separate containers. This fuel is poured or sprayed on to the charcoal which is then ignited by means of a match or other suitable kindling instrument. After the liquid fuel has ignited the lumps or briquettes of charcoal, and these have burned sufficiently to produce a bed of glowing coals, the fuel is then in proper condition for the barbecuing of the meats.

It has previously been proposed to avoid the use of the starter fuels, and also to avoid the necessity of handling the lumps or briquettes of charcoal which some persons find objectionable, by packaging the lumps or briquettes in combustible containers which are, themselves, capable of ignition. Once successfully ignited, the container, consisting usually of paper or wood pulp, continues to burn and ignite the lumps or briquettes of charcoal. This type of packaged charcoal is described in US. Patents 2,955,- 029 and 3,010,809. As stated in the latter patent, such packages have generally been too expensive to manufacture or difiicult to ignite, or inconsistent in operation after ignition because of failure to fire the charcoal rapidly or uniformly, and often required actual tearing of the packages in order to properly ignite them. In spite of certain improvements that have been made as disclosed in the foregoing patents, which in turn were improvements over the prior types of packaged lump or charcoal briquettes some of the recited problems have not been solved completely.

It has also been proposed to treat charcoal fuel with an igniter fuel, followed by packaging. For example, a procedure is described in U.S. Patent No. 2,963,352 whereby charcoal fuel is impregnated with a low boiling alcohol, and then hermetically sealed in a metal container. While this has solved the problem of or the necessity of the user having to treat the briquettes with a starter fluid, the container must be opened and the briquettes poured therefrom on to the grill and possible handling by the user before ignition.

It is an object of the present invention to provide a package ofburnable charcoal impregnated with its own starter fluid, the impregnated fuel being sealed in a plastic container which can itself be readily ignited to sustain a flame suflicient to ignite the starter fluid and in turn ignite the solid fuel.

It is a further object of this invention to provide a completely packaged, readily ignitable charcoal fuel suit able for the barbecuing of meats consisting of an easily handled, pre-packaged charcoal fuel which need merely be placed on a grill and ignited without the necessity of handling the briquettes themselves or using starter fluids.

It is a further object of this invention to provide a prepackaged charcoal fuel suitable for barbecuing meats wherein the fuel contains its own starter fluid which cannot escape from the package during storage, and wherein the package itself is substantially transparent so that the contents thereof can be easily inspected by the purchaser.

The above and other objects of the present invention will be apparent from the following description thereof and which broadly includes impregnating a plurality of pieces of charcoal with an essentially paraflinic petroleum hydrocarbon fraction having a boiling range (5 to by volume) of about 350 to 400 F. The impregnated pieces of charcoal are then sealed in a plastic, substantially transparent container consisting essentially of a 2 or 3 ply laminate of plastic film. The films which we Tmploy in preparing our laminate containers are as folows:

(1) A coated cellophane (regenerated cellulose) film having a weight of from about 15,000 to 30,000 square inches per pound.

(2) A coated polypropylene (polymerized propylene) film having a thickness of from about 0.5 to 0.7 mil.

(3) A nylon film having a thickness of about 0.5 mil.

Sheets of the above films are laminated by use of adhesives such as solutions of polyvinylidene chloride, rubher, neoprene, polyisobutylene and various starches.

We may use a 2 ply laminate in which one ply consists of coated cellophane film. The coating is preferably a polyvinylidene chloride polymer which has been dissolved or suspended in an organic solvent and applied to both sides of a cellophane film in a thin coating. Typically, this cellophane film will have a weight or gauge of 19,500 square inches per pound, or cellophane film of slightly higher weight, for example 25,000 square inches per pound is laminated to one side of another lighter weight film, leaving a small amount of residual solvent between the plies. The coated side of the film is allowed to dry and the coating serves as a sealant for the final package when this side of the film is used as the inside face of the package.

Alternatively, a biaaxially oriented polypropylene film having a thickness of 0.5 mil when coated on one side with a solution or suspension of a polyvinylidene chloride polymer, is then laminated on the coated .side with a film of cellophane, leaving a small residual amount of solvent between the plies. Here again, the exposed. side of the cellophane film is also coated with the same polymer in order to utilize its plastic properties in the final heat sealing operation Where the seams are heat sealed to close the final package.

Another alternative, a 3 ply plastic sheeting material is formed by apply a polyvinylidene chloride polymer coating to both sides of a biaxially oriented polypropylene film after which a nylon film having a thickness of about 0.5 mil is laminated to one side of the coated polypropylene film and a cellophane film is laminated to the other side of the polypropylene film. Here again, it is preferable to leave a small amount of residual solvent from the coating between the plies of the laminate. Also, the exposed side of the cellophane film in the 3 ply laminate has a coating of polyvinylidene chloride polymer.

The two or three ply plastic sheeting is formed into containers such as bags. The lump or briquetted charcoal, impregnated with the aforementioned starter fluid, is then placed in the containers which are then sealed by heating the unsealed top or other unsealed edges of the bag by applying heat to the edges. The inner, coated cellophane plies are heated in pressure contact with each other to weld them thereby affording a perfect seal which prevents the scape of the starter fluid vapors. The impregnated solid charcoal is readily visible through the 2 or 3 ply plastic film.

Prior to forming the 2 or 3 ply plastic film or sheeting material into bags, it can be suitably lithographed or printed with labels, advertising material or identification.

The lump or briquetted charcoal which we employ can be obtained from several sources:

(1) By carbonizing various hardwoods such as oak, hickory, ash, etc., in an inert atmosphere to obtain what is known in the trade as hardwood charcoal. This can be used either in lump form or, after grinding or screening, it can be briquetted by employing starch or other binders in accordance with processes well known to those skilled in the art.

(2) By carbonizing various natural cellulosic materials such as sawdust, woodbark, corn cobs, etc., in an inert atmosphere to produce a finely divided carbon which is then briquetted with binders in accodance with well known pocedures.

(3) By employing the type of carbon whose manufacture is described in US. Patent 3,173,769 issued to Martin et al. as a finished briquette produced in accordance with the procedures described in said patent.

As previously stated, the starter fluid which is used to impregnate the lump or briquetted charcoal fuel is an essentially paraffinic petroleum hydrocarbon fraction. Preferably this material will have a boiling range of about 350 to 400 F., this covering the 5 to 95% by volume portion of the material. This fluid is readily ignited in contact with a flame and burns with a sufficient quantity of heat to ignite the solid portion of the charcoal fuel resulting in a bed of glowing coals which is ultimately desired by the user. When the edges of the 2 or 3 ply plastic bag have been properly sealed, as described herein, the vapors from this fluid will not penetrate the package, this being primainly due to the characteristics of the laminated film package.

When the quantity of starter fluid which we employ as an impregnant for our char fuel is not critical, we have found that from about to 20% by weight of the fuel, based on the weight of the briquettes, is particularly useful.

When a 3 ply laminate is used, the center ply of polypropylene film is preferably biaxially oriented to insure optimum strength and burning characteristics of the combination multi-ply bag.

In employing the pro-packed charcoal fuel of our invention, all that the user need do is select an appropriate number of bags of the fuel, place them on a grate, and ignite them with a match. The plastic laminate will ignite and burn easily, and in turn ignites the starter fluid impregnated in the charcoal or briquettes. Within from 5 to minutes, all of the package material and the starter fluid has been consumed and the briquettes have formed a bed of glowing coals for use in barbecuing meat.

Example I In a specific embodiment of our invention, a plurality of charcoal briquettes are either soaked or sprayed with about by weight of a paraffinic petroleum hydrocarbon fraction having a boiling range of about 350 to 400 F. (5% to 95% by volume). The impregnated briquettes were then placed in a 3 ply plastic container in which the inner ply (adjacent to the briquettes) is a coated (polyvinylidene chloride polymer) cellophane film having a weight of 20,000 square inches per pound; the center ply is a coated polypropylene film having a thickness of about 0.7 mil; and the outer film consists of a nylon film, having a thickness of about 0.5 mil. A 3 ply laminate is prepared by taking film sheeting material of the three types of film and laminating them at about 150 to 200 F. by applying a solution of an adhesive to both sides of the polypropylene film followed by passing the films through pressure rolls for lamination while leaving a small amount of solvent in the laminate. The 3 ply film is then printed, if desired, after which it is cut into appropriate pieces to produce the size container desired.

After the impregnated briquettes have been placed in the bags, the open portions of the bags are sealed by placing the edges of the open portions in a heating element operated at a temperature of 245 to 275 F. The edges are maintained in the heating elements for a time suflicient to permit the temperature of the interior cellophane film to reach about 150 F., thereby causing the coating on the cellophane film to soften slightly and the contact surfaces are bonded together.

In order to barbecue meat with the above described prepackaged fuel product, it is only required to place one or more of the packages on a barbecue grill, ignite the packages with a match and wait about 12 minutes after which time the briquettes will form a glowing bed of coals.

Example 11 In this example, briquettes manufactured in accordance with the process described in US. Patent 3,173,769 were used. The type and amount of starter fuel and the type of package employed were the same as Example 1. Equally good results insofar as ignition and fuel value are concerned, were obtained in this instance as compared to the product in Example I.

Example III Laminate containers for impregnated briquettes are also made according to our invention by laminating coated cellophane film and polypropylene film having the weight or thickness previously specified herein; or a cellophane film can be laminated to a nylon film. In either case, the cellophane and polypropylene films are coated with polyvinylidene chloride and the films are laminated by heating, but preferably by using a solvent glue wherein a small residual portion of the solvent remains in the laminate.

It will be obvious to those skilled in the art that various changes or departures may be made from the foregoing description within the scope of our invention and, therefore, the invention is not limited to the specific details described herein but only in accordance with the appended claims.

We claim:

1. A package of charcoal fuel which is capable of ready ignition and continuous burning without the use of auxiliary starter fuel, consisting essentially of a plurality of pieces of charcoal impregnated with from about 10 to 20% by weight of an essentially paraflinic petroleum hydrocarbon fraction, the 5 to volume portion having a boiling range of about 350 to 400 F., and said impregnated charcoal pieces being sealed in a plastic container consisting essentially of a 3 ply laminate of (l) coated cellophane film having a weight of from about 15,000 to 30,000 square inches per pound, (2) coated polypropylene film having a thickness of about 0.5 to 0.7 mil, and (3) nylon film having a thickness of about 0.5 mil, the cellophane film and the nylon film forming the inner and outer plys, respectively, of said laminate container, said cellophane and polypropylene films being coated on both sides with an adhesive polymer containing a residual amount of organic solvent to said films.

2. A product according to claim 10 wherein the charcoal fuel is made from hardwood charcoal.

3. A product according to claim 10 wherein the charcoal is made by partially carbonizing a bituminous material selected from the group consisting of high and low medium volatile coals and lignite.

4. A product accordingly to claim 10 wherein the polypropylene film ply in the laminate consists of biaxially oriented polypropylene.

5. A package of charcoal fuel which is capable of ready ignition and continuous burning without the use of auxiliary starter fuel, consisting essentially of a plurality of pieces of charcoal impregnated with from about 10 to 20% by Weight of an essentially paralfinic petroleum hydrocarbon fraction, the 5 to 95% volume portion having a boiling range of about 350 to 400 F., said impregnated charcoal pieces being sealed in a plastic container consisting essentially of a 2 ply laminate of (1) coated cellophane film having a weight of from about 15,000 to 30,000 square inches per pound and (2) a film selected from the group consisting of coated polypropylene film having a thickness of about 0.5 to 0.7 mil and nylon film having a thickness of about 0.5 mil, the cellophane film forming the inner ply of said laminate container, said cellophane and polypropylene films being coated on both sides with an adhesive polymer containing a residual amount of organic solvent used in applying the coating to said film.

References Cited UNITED STATES PATENTS FOREIGN PATENTS Great Britain. Great Britain.

15 DANIEL E. WYMAN, Primary Examiner.

C. F. DEES, Assistant Examiner. 

1. A PACKAGE OF CHARCOAL FUEL WHICH ISCAPABLE OF READY IGNITION AND CONTINUOUS BURNING WITHOUT THE USE OF AUXILIARY STARTER FUEL, CONSISTING ESSENTIALLY OF A PLURALITY OF PIECES OF CHARCOAL IMPREGNATED WITH FROM ABOUT 10 TO 20% BY WEIGHT OF AN ESSENTIALLY PARAFFINIC PETROLEUM HYDROCARBON FRACTION, THE 5 TO 95% VOLUME PORTION HAVING A BOILING RANGE OF ABOUT 350 TO 400%F., AND SAID IMPREGNATED CHARCOAL PIECES BEING SEALTED IN A PLASTIC CONTAINER CONSISTING ESSENTIALLY OF A 3 PLY LAMINATE OF (1) COATED CELLOPHANE FILM HAVING A WEIGHT OF FROM ABOUT 15,000 TO 30,000 SQUARE INCHES PER POUND, (2) COATED POLYPROPYLENE FILM HAVING A THICKNESS OF ABOUT 0.5 TO 0.7 MIL, AND (3) NYLON FILM HAVING A THICKNESS OF ABOUT 0.5 MIL, THE CELLOPHANE FILM AND THE NYLON FILM FORMING THE INNER AND OUTER PLYS, RESPECTIVELY, OF SAID LAMINATE CONTAINER, SAID CELLOPHANE AND POLYPROPYLENE FILMS BEING COATED ON BOTH SIDES WITH AN ADHESIVE POLYMER CONTAINING A RESIDUAL AMOUNT OF ORGANIC SOLVENT TO SAID FILMS. 